Autism Spectrum Disorder Signs and Symptoms

The American Academy of Child and Adolescent Psychiatry notes that poor or absent eye contact is a hallmark feature of autism, particularly noticeable in preschool children 3
Marked lack of interest in other people is a characteristic of autism, in stark contrast to the profound social interest of normal infants 1
Failure to respond to name when called is often an early sign of autism, leading parents to worry the child might be deaf 1
Impaired peer relationships, with lack of interest in playing with other children, are common in autism 1, 4
Absent or limited use of gestures in communication, such as not pointing to show interest or using conventional gestures, is a key feature of autism 5
Lack of imaginative or make-believe play that would be developmentally appropriate is a characteristic of autism 1

Communication and Language Abnormalities

Delayed or total lack of spoken language, with no attempt to compensate through alternative means, is a common feature of autism 1
Language regression, where a child speaks and then stops, is a less common but significant symptom of autism 3
Echolalia, or the immediate or delayed repetition of words or phrases, is a characteristic of autism 1
Pronoun reversal, such as saying "you" instead of "I", is a common language abnormality in autism 1
Stereotyped, repetitive, or idiosyncratic language patterns are often seen in autism 1
Concrete, literal interpretation of language is a characteristic of autism 1
One-sided, pedantic speech in higher-functioning individuals, often focused on circumscribed interests, is a feature of autism 2

Stereotyped motor mannerisms, such as hand flapping, finger mannerisms, or body rocking, are common in autism 1, 3
Extreme distress with changes in routine or environment, with marked resistance to transitions, is a characteristic of autism 1, 3
Adherence to apparently nonfunctional routines or rituals is a feature of autism 1
Encompassing preoccupations with restricted topics or objects are common in autism 1
Persistent preoccupation with parts of objects rather than their intended use is a characteristic of autism 1
Self-stimulatory behaviors, which may include self-injury, are often seen in autism 1

Infants and toddlers with autism may seem "too good" and undemanding, and may not respond to their name by 12 months 5
Preschool-age children with autism often show marked lack of interest in peers, absent or severely delayed speech and communication, and restricted interests 1, 4
School-age and adolescent children with autism may show increased social and communication skills, but deficits persist, and problems with change and transitions may become more prominent 1

The male-to-female ratio in autism is approximately 4:1, though females with autism tend to have more severe intellectual disability 2
Two behaviors consistently differentiate autistic children from language-impaired peers: pointing for interest and use of conventional gestures 5
The presence of communicative speech by age 5 years is a positive prognostic indicator, while its absence is a negative predictor of ultimate outcome 1, 3

Children with autism have substantially elevated rates of epilepsy, with approximately 20-25% having EEG abnormalities or seizure disorders 1
Increased risk for accidental death, particularly drowning, is a concern for children with autism 1